.wrap {
  height: 300px;
  overflow: auto;
  border: 1px solid #eee;
}

.left {
  .item {
    background-color: #eee;
    width: 100px;
    min-height: 50px;
    align-items: center;
    justify-content: center;
    display: flex;
    box-sizing: border-box;
    &.active {
      border-right: 5px solid blue;
    }
  }
}

.right {
  .item {
    margin-bottom: 20px;
    width: 110px;
    height: 200px;
    background-color: red;
    &.active {
      background-color: yellow;
    }
  }
}